Answer:
Explanation:18kt alloy contains
i) 75% of gold
rhogold=19.3g/cm^3
=75/100×19.3
=14.475g/cm^3
ii) 16% of silver
rhosilver=10.5g/cm^3
=16/100×10.5
=1.68g/cm^3
iii) 9% of copper
rhocopper =8.90g/cm^3
=9/100×8.9
=0.801g/cm^3
Overall density of 18kt gold
=(0.801+1.68+14.475)g/cm^3
=16.956g/cm^3
=17g/cm^3 to 3s.f
False because your deltoids are in your shoulders not your back
It is D,Copernicus.when he first proposed the idea everyone thought he was nuts and that it was not plausible.even though his theory wasn't so accurate it still helped further scientific research.HE was born February 19,1473 and he published a book about his theory.
